This invention relates to a method and apparatus for use in the molding of articles of manufacture, wherein a hardenable liquid forms a portion of the molded article.
Various molding methods are discussed in Chapters 4 and 5 of the book entitled "Handbook of Reinforced Plastics", Society of the Plastics Industry, Inc., copyright 1964, published by the Reinhold Publishing Corporation, Library of Congress Catalog Card No. 64-15205. Whenever contact molding, bag molding, or similar procedures are used to fabricate articles of manufacture formed from fiber reinforced plastic, single die molds will typically be required. Whenever higher pressures are necessary, such as in premix or preform molding, matched die molds will be necessary.
To economically produce these articles using any type of mold, the rate of article production must be maximized to allow quick recovery of the capital cost associated with the purchase of the mold. The mold cycle time must be minimized. In the case of an article that incorporates fibers or filaments within the hardenable liquid, it is desirable to quickly wet these materials. In the case of an article that is comprised entirely of a hardenable liquid, (typically a thermosetting resin), it is desirable to have the liquid quickly flood the mold cavity such that the curing time of the resin may be kept to a minimum.
A method and apparatus therefore need be developed that permits rapid flow of the resin throughout the mold and, when fibers are used to make the article, permits rapid wetting of these fibers.